savePurposes() only checked that each key was a nonempty string, so a
stale or tampered mailbox key (reachable by posting straight to
/livewire/update) saved successfully while MailboxResolver silently
returned null for it. Every purpose's key must now name a mailbox that
exists; system's must additionally be active, since every unmapped or
inactive OTHER purpose falls through to it.
EditMailbox::save() also cleared last_verified_at only when the
password changed, but smtpUsername() depends on address and username
too (falling back to address when username is blank) — changing
either while leaving the password untouched kept showing a successful
verification for an identity nothing had actually tested.
I3: nothing stopped an operator unchecking Aktiv on the mailbox that
mail.purpose.system points at. MailboxResolver::active() filters an
inactive mailbox at BOTH the direct lookup and the system fallback, so
that one checkbox could take mail.purpose.system to null and every
purpose without its own mapping down with it — the existing
system_required guard on savePurposes() reads as if this were covered,
but it only blocks the empty-mapping path, not this one.
EditMailbox::save() now refuses active=false against the mailbox 'system'
currently points at, the same way savePurposes() already refuses to leave
'system' empty.
I4: Admin\Mail::saveServer() writes mail.host — the platform's outbound
relay for every purpose mailbox at once — and CloudReady::toMail() puts a
customer's Nextcloud admin password in cleartext in the message body. So a
signed-in mail.manage session was already a credential-interception
primitive, the same threat Admin\Secrets' second gate exists for. Both
saveServer() and EditMailbox::save() (only when a new password is actually
being typed) now also require passwordRecentlyConfirmed(), following the
ConfirmsPassword pattern Secrets.php and Settings.php's two-factor actions
already use — including their per-action UI shape (an inline confirm form
scoped to the gated action), not a whole-page lock, so address, display
name, username, no-reply, active and the purpose mapping stay reachable
without confirming, per the brief's capability split.
Both gated and ungated paths are covered by tests, and both guards were
mutated away and confirmed to fail before being restored.
EditMailbox::save() now checks SecretCipher::isUsable() before touching a
typed password and reports it as a form error, instead of letting
SecretCipher::encrypt() throw all the way to Laravel's debug page. Also
switches the mail.manage migration to Role::findOrCreate, matching every
sibling capability migration, so a squashed replay can't hit
RoleDoesNotExist.